Clear aqueous gels are prepared from certain polyethers, surfactant and water. These gels are particularly useful in the formation of topically applied cosmetic and pharmaceutical compositions.
The prior art teaches that in order to form gels in formulations containing polyoxyethylene-polyoxypropylene block polymers, it is necessary to include a gelling agent. For example, U.S. Pat. No. 2,773,801 teaches the use of natural and synthetic gums and gum-like materials as gelling agents. British Pat. No. 786,346 teaches that it is necessary to treat a hydroxy polymer with a complex condensation product of one mole of a compound of the formula Ti(OR).sub.4, wherein R is an alkyl radical of 1 to 8 carbon atoms with 1/2 to 4 moles of a saturated C.sub.2 -C.sub.6, aliphatic hydroxy mono-, di-, or tri-carboxylic acid to obtain gellation. It has also been reported by W. Schonfeldt ("Surface Active Addition Products of Ethylene Oxide") that nonyl phenols with 40 or more moles of ethylene oxide added thereto do not form gels in an aqueous solution.
U.S. Pat. No. 3,639,574 relates to hydrogen peroxide gels prepared employing certain polyoxyethylene polyoxypropylene block copolymers as gelling agents. U.S. Pat. No. 3,740,421 relates to polyoxyethylene-polyoxypropylene aqueous gels. Polyoxyethylene-polyoxypropylene block copolymers form gels within certain specified ranges of compositions with water. U.S. Pat. No. 3,579,465 relates to polyoxyethylene-polyoxypropylene adducts of ethylene diamine which, within specified limits form aqueous gels.
The latter two patents required incorporation of the polyoxyethylene-polyoxypropylene compounds in amount of from about 20 to 90 weight percent in the gel composition.
U.S. Pat. No. 4,465,663 discloses the production of clear aqueous gels from polyoxybutylene-polyoxyethylene block copolymers employed in an amount of about 16 to 84 percent by weight. For economic reasons, it would be desirable to be able to produce gels from polyalkylene compounds with or without other surfactants wherein the amount of said compounds including any additional surfactants is much less than the minimum 16 percent of the above prior art patents, preferably below 5 percent.
Accordingly, it is a purpose of the instant invention to provide organic polymer gels particularly suitable for use in cosmetic and pharmaceutical formulations from polyoxyalkylene compounds and another surfactant.